aberrant crypt foci

Background: Colon cancer (CC) is the third commonly diagnosed cancer and the second leading cause of mortality in the US when compared to India where prevalence is less. Possible reason could be the vegetarian diet comprising spices used in curry powders. Researchers believe that 70% of the cases are associated with diet. Spices have inherited a rich tradition for their flavor and medicinal properties. Researchers have been oriented towards spices present in food items for their antitumorigenic properties. Objective: We investigated the effects of sambar as a preventive measure for 1,2-dimethyl hydrazine (DMH)-induced CC in Wistar albino rats. Materials and Methods: The animals were divided into three groups (n = 6) namely control, DMH, and sambar. At the end of the experimental period, the animals were killed using anesthesia and the colons and livers were examined. Results: All the treatment groups exhibited a significant change in the number of aberrant crypt foci (ACF). Sambar group showed a significant change in the colonic GSH when compared to both normal and DMH groups. A significant reduction in the liver GSH was noted in the sambar group. Only sambar group showed a significant change in the liver catalase levels when compared to DMH. There was a significant reduction in the colonic nitrite in the sambar-treated group; 2.94 ± 0.29 when compared to DMH control at 8.09 ± 1.32. On the contrary, a significant rise in the liver nitrite levels was observed in the sambar-treated rats. Conclusion: Sambar may prevent the risk of CC when consumed in dietary proportions.

Quercus infectoria Olivier (Fagaceae) which contains abundant amount of hydrolysable tannins and traces of gallic acid, ellagic acid and sitosterol
is reported to be effective in inflammatory bowel disease. In the present study, chemopreventive potential of acetone extract of Q.
infectoria (AEQI) 450 mg/kg was assessed in 1,2-dimethylhydrazine (DMH) (20 mg/kg) induced colon cancer. DMH produced significant
development of aberrant crypts (AC) and aberrant crypt foci (ACF) associated with loss of body weight and high mortality. Treatment
of rats with AEQI not olnly prevented development of AC and ACF but also reduced mortality and loss of body weight. There was a
significant increase in oxidative stress (increase in MDA, MPO, NO and decrease in SOD) as well as TNF α, TGF β and VEGF. Treatment
with AEQI decreased not only oxidative stress but also oxidative stress and inflammatory factors. Our data suggest that Q. infectoria
possesses potential anti carcinogenic activity against colon cancer. Decrease in growth factors and anti oxidant activity may be responsible
for this anti carcinogenic effect.

Low dietary folate intake is associated with an increased risk for colon cancer; however, relevant genetic animal models are lacking. We therefore investigated the effect of targeted ablation of two folate transport genes, folate binding protein 1 (Folbp1) and reduced folate carrier 1 (RFC1), on folate homeostasis to elucidate the molecular mechanisms of folate action on colonocyte cell proliferation, gene expression, and colon carcinogenesis. Targeted deletion of Folbp1 (Folbp1(+/-) and Folbp1(-/-)) significantly reduced (P < 0.05) colonic Folbp1 mRNA, colonic mucosa, and plasma folate concentration. In contrast, subtle changes in folate homeostasis resulted from targeted deletion of RFC1 (RFC1(+/-)). These animals had reduced (P < 0.05) colonic RFC1 mRNA and exhibited a 2-fold reduction in the plasma S-adenosylmethionine/S-adenosylhomocysteine. Folbp1(+/-) and Folbp1(-/-) mice had larger crypts expressed as greater (P < 0.05) numbers of cells per crypt column relative to ...

Colon cancers are the result of the accumulation of multiple genetic alterations. To evaluate the role genomic instability plays during tumor development, we compared DNA fingerprints of 44 aberrant crypt foci (ACF; the earliest identified neoplastic lesion in the colon), 23 cancers, and normal crypts generated by random primers with PCR. The PCR products, separated by PAGE and viewed after silver staining, demonstrate altered fingerprints for 23.3% of the ACF and 95.7% of the cancers. In this first study of human ACF with this approach, the finding of altered DNA fingerprints in these microscopic lesions suggests that genomic instability can occur very early in human colon tumorigenesis.

Oxidative stress has been proposed to be involved in colorectal cancer development. Many dark pigments of plants have potent oxidative stress preventive properties. In this study, unpolished Thai rice was assessed for antioxidant activity using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) methods. Red strain unpolished Thai rice was also administered to rats exposed to azoxymethane (AOM) for induction of aberrant crypt foci (ACF). Serum malondialdehyde (MDA) and ferric reducing antioxidant power (FRAP) were investigated for cellular oxidative stress and serum antioxidants, respectively. Red pigment unpolished Thai rice demonstrated high antioxidant activity and was found to significantly and dose dependently decrease the total density and crypt multiplicity of ACF. Consumption of Thai rice further resulted in high serum antioxidant activity and low MDA cellular oxidative stress. Interestingly, the density of ACF was strongl...

Functional foods include antioxidant nutrients which may protect against many human chronic diseases by combating reactive oxygen species (ROS) generation. The purpose of the present study was to investigate the protective effect of pomegranate peel extract (PPE) on azoxymethane (AOM)-induced colon tumors in rats as an in vivo experimental model. Forty Sprague-Dawley rats (4 weeks old) were randomly divided into 4 groups containing 10 rats per group, and were treated with either AOM, PPE, or PPE plus AOM or injected with 0.9% physiological saline solution as a control. At 8 weeks of age, the rats in the AOM and PPE plus AOM groups were injected with 15 mg AOM/kg body weight, once a week for two weeks. After the last AOM injection, the rats were continuously fed ad-libitum their specific diets for another 6 weeks. At the end of the experiment (i.e. at the age of 4 months), all rats were killed and the colon tissues were examined microscopically for lesions suspected of being preneopl...

A sucrose-rich diet has repeatedly been observed to have cocarcinogenic actions in the colon and liver of rats and to increase the number of aberrant crypt foci in rat colon. To investigate whether sucrose-rich diets might directly increase the genotoxic response in the rat colon or liver, we have added sucrose to the diet of Big Blue rats, a strain of Fischer rats carrying 40 copies of the lambda-phage on chromosome 4. Dietary sucrose was provided to the rats for 3 weeks at four dose levels including the background level in the purified diet [3.4% (control), 6.9%, 13.8%, or 34.5%] without affecting the overall energy and carbohydrate intake. We observed a dose-dependent increase in the mutation frequency at the cII site in the colonic mucosa with increased sucrose levels, reaching a 129% increase at the highest dose level. This would indicate a direct or indirect genotoxic effect of a sucrose-rich diet. No significant increase in mutations was observed in the liver. To seek an expl...

Cell adhesion in the normal colon is typically associated with differentiated cells, whereas in cancerous colon it is associated with advanced tumors. For advanced tumors growing evidence supports the existence of stem-like cells that have originated from transdifferentiation. Because stem cells can also be transformed in their own niche, at the base of the Lieberkühn's crypts, we conjectured that cell adhesion can also be critical in early tumorigenesis. To assess this hypothesis we built an annotated, multi-valued logic model addressing cell adhesion of normal and tumorigenic stem cells in the human colon. The model accounts for (i) events involving intercellular adhesion structures, (ii) interactions involving cytoskeleton-related structures, (iii) compartmental distribution of α/β/γ/δ-catenins, and (iv) variations in critical cell adhesion regulators (e.g., ILK, FAK, IQGAP, SNAIL, Caveolin). We developed a method that can deal with graded multiple inhibitions, something whic...

With cancer being one of the major causes of death around the world, studies are ongoing to find new chemotherapeutic leads. There are common mechanisms for colorectal cancer (CRC) formation. Several are connected with oxidative stress-induced cell apoptosis and others are related to imbalanced homeostasis or intake of drugs/toxins. Plants that have been used for decades in folk and traditional medicine have been accepted as one of the commonest sources of discovered natural agents of cancer chemotherapy and chemoprevention. The aim was to study the antioxidant and chemopreventive effects of Strobilanthes crispus on colorectal cancer formation. Five groups of rats were injected subcutaneously with AOM, 15 mg/kg body weight, each once weekly for 2 weeks. The cancer group was continued on 10 % Tween-20 feeding for 8 weeks. The standard drug group was continued on 35 mg/kg 5-fluorouracil intraperitoneal injection twice a week for 8 weeks, and the experimental groups were continued on 2...

Sulindac, atorvastatin, or prebiotic dietary fiber may reduce colorectal cancer (CRC) risk. However, clinical trial data are currently limited. We conducted a randomized, phase II chemoprevention trial involving subjects 40 years or older, with previously resected colon cancer or multiple/ ...

Background: Sulforaphane (SFN), a phytochemical compound, which belongs to isothiocyanates family found in abundance in broccoli sprouts, potently induces a variety of antioxidant enzymes via nrf2-keap1 mediated pathway, thereby protects cells from injury induced by various kinds of oxidative stresses. We have previously shown that SFN protects gastric mucosa from oxidative injury induced by H. pylori infection. SFN also down-regulates histone deacetylase (HDAC) activity, thereby induces apoptosis and inhibits proliferation of tumor cells in variety of tissues. On the other hand, colon cancer has been increasing in Japan. Since numerous epidemiological studies have shown that colon cancer is inversely associated with intake of anti-oxidant vegetables, we examined if dietary SGS prevents colon tumorigenesis in mice, and in human subjects.
Methods:  1. Effects of SFN on Colonic tumorigenesis in Mice Treated with Chemical Carcinogen: Effects of SFN on colonic tumorigenesis were examined in the ICR male mice, pretreated with a chemical carcinogen, azoxymethane (AOM) (15 mg/kg). The AOM-treated mice were fed for 8 weeks with or without sulforaphane glucosinolates (SGS: 2,200 ppm/kg/day), which is a precursor of SFN. Effects of SGS treatment on formation of the microscopic aberrant crypt foci (ACF), and the macroscopic tumors in colonic mucosa were evaluated. 2. Effects of SFN on formation of Colonic Aberrant Crypt Foci (ACF) in patients with colonic adenoma: Effects of intake of raw broccoli sprouts (BS), 50 g/day, which contains 220 mg SGS every other day, for 6 months on changes in the number of ACF in rectal mucosa was examined by colonoscopy in patients with colonic adenoma. 3. Effects of SFN on intestinal microbiota in human subjects:  Effects of dietary intake of raw broccoli sprouts (BS), 20 g/day, which contains 88 mg SGS every other day, for 2 weeks on intestinal microbiota in healthy volunteers was assessed by measuring composition of stool bacteria, using T-RFLP method. In human studies, alfalfa sprouts, which contains no SFN was used as a placebo control.
Results: 1. Daily administration of SGS suppressed formation of microscopic ACF and macroscopic colonic tumors in the AOM-pretreated mice in vivo. 2. Intake of BS for 6 months tended to decrease the number of colonic ACF in patients with colonic adenoma. 3. Intake of BS for 2 weeks increased percentages of Bifidobacterium and Clostridium XVIa, which has been shown to enhance protection of colonic mucosa by increasing butyrate production in colonic lumen.
Conclusions: 1. SFN affords chemoprotection against colonic cancer, presumably by up-regulating nrf2-dependent antioxidant enzymes in normal colonic epithelial cells, and by inducing apoptosis of colonic tumor cells through inhibition of HDAC activity. The present study further suggests that changes in intestinal microbiota by SFN, may play a role in chemoprevention against colon cancer.

Kefir is a probiotic fermented milk product produced from grains with a complex composition of bacteria and yeasts that live in a symbiotic association. Anti-proliferative, anti-inflammatory, and anti-mutagenic effects are some of the health beneficial properties of kefir grains. The present study was conducted to evaluate whether regular consumption of kefir milk would be capable of preventing the development of pre-neoplastic lesions induced by azoxymethane (AOM). Aberrant crypt foci were induced in BALB-c mice via 2 subcutaneous injections of azoxymethane (15 mg/kg) and kefir was administered by daily gavage for 8 weeks (5 ml/kg). Additionally, bacterial growth was monitored in pasteurized and ultra-high temperature (UHT) treated milk to compare different fermentation conditions. Our results showed that UHT milk presented better growth of Lactobacillus acidophilus colonies. The aberrant crypt foci were attenuated by approximately 43% (height) and 20% (width) in the kefir group co...

The major food items of Indian cuisine include rice, wheat, diary products, and abundant fruits and vegetables. Beside these, there are several kinds of herbs and spices as important ingredients, containing many phytochemicals with medicinal properties, adding taste to Indian cuisine. An impressive body of data exists in support of the concept that Indian food ingredients can be used in preventive strategies aimed at reducing the incidence and mortality of different types of cancers because of their antioxidative, antimutagenic and anticarcinogenic properties. Vital ingredients used in Indian cooking include turmeric, cloves, ginger, aniseed, mustard, saffron, cardamom and garlic Garlic is an indispensable ingredient of Indian food and this report concerns the chemopreventive efficacy of garlic in an azoxymethane induced rodent colon carcinogenesis model. The effect of garlic was evaluated in terms of aberrant crypt foci, putative preneoplastic lesions in the colon. In addition, cel...

The potential of purple corn color (PCC), a natural anthocyanin, to modify colorectal carcinogenesis was investigated in male F344/DuCrj rats, initially treated with 1, 2-dimethylhydrazine (DMH), receiving 2-amino-1-methyl-6-phenylimidazo [4, 5-b] pyridine ( ...

Malignant neoplasms, including colon cancers, are thought to arise from a single initiated progenitor cell. Aberrant crypt foci (ACF) are putative precursors of at least some colon cancers. The pattern of X chromosomal inactivation, which is identified by the differential methylation of a site near a polymorphic CAG repeat in the androgen receptor gene, was used to determine the clonality status of 11 ACF from eight female patients. Ten of 11 ACF were found to be monoclonal aberrations. The eleventh ACF appeared monoclonal, but nonrandom inactivation of the X chromosome was also seen in normal crypts from this patient. These results clearly demonstrate that: (a) a high percentage of ACF lesions are neoplastic rather than hyperplastic; and (b) ACF are the earliest identified neoplastic lesions in the colon.

The global obesity / diabetes epidemic has resulted in robust increase in the incidence of colorectal cancer (CRC). Epidemiological, animal and human studies have indicated efficacy of (n-3) PUFA in chemoprevention of sporadic and genetic-driven CRC. However, diabetes-promoted CRC presents a treatment challenge that surpasses that of sporadic CRC. This report analyzes the efficacy of (n-3) PUFA generated by the fat-1 transgene that encodes an (n-6) to (n-3) PUFA desaturase, and of synthetic (n-3) PUFA mimetic (MEDICA analog), to suppress CRC development in carcinogen-induced diabetes-promoted animal model. Carcinogen-induced CRC is shown here to be promoted by the diabetes context, in terms of increased aberrant crypt foci (ACF) load, cell proliferation and epithelial dedifferentiation, being accompanied by increase in the expression of HNF4α, β-catenin, and β-catenin-responsive genes. Incorporating the fat-1 transgene in the diabetes context, or oral MEDICA treatment, resulted in a...

Many epidemiological and experimental studies have suggested an important role for dietary fibre (DF) of cereals in the prevention of colon cancer. The objective of the present study was to explain the effects of the DF of barley Rihane (BR) on azoxymethane (AOM)-induced aberrant crypt foci (ACF) and colonic bacterial diversity in rats. Following an acclimatisation period, rats were divided into four groups and fed a control (C) diet or experimental diet containing 30 % of BR. DF content in the experimental diet was twice that of the C diet (total DF was 8·69 % in the C diet and 15·24 % in the BR diet). At 7 and 8 weeks of age, rats received two successive subcutaneous injections of AOM at 20 mg/kg body weight. At 12 weeks after the first injection, ten animals from each group were killed. The BR diet decreased colonic pH (P < 0·05) compared with the C diet. The total number of ACF observed decreased considerably in the BR/AOM group compared with the C/AOM group (P < 0·05). Co...